It is useful to fasten members to a plastic molded wall. Common fastening methods include bonding and welding. Mechanical fasteners are also used as exemplified by U.S. Pat. No. 5,067,575, assigned to Ford Motor Company, which teach integrally molding a socket into a blow-molded wall. A peg fastening means attaches within the socket to provide an attachment point for a member. This invention is primarily directed towards bonding items to the exterior surface of a blow-molded container. When attaching articles to the interior container, it becomes difficult to form the socket. The present invention is directed toward a method of forming an inwardly directed projection for attaching articles. This invention is especially useful in attaching articles to the interior of a blow-molded container such as a fuel tank while maintaining a leak proof structurally sound exterior wall.